Plant cells divide their cytoplasmic content by forming a new membrane compartment, the cell plate, via a rerouting of the secretory pathway toward the division plane aided by a dynamic cytoskeletal ...apparatus known as the phragmoplast. The phragmoplast expands centrifugally and directs the cell plate to the preselected division site at the plasma membrane to fuse with the parental wall. The division site is transiently decorated by the cytoskeletal preprophase band in preprophase and prophase, whereas a number of proteins discovered over the last decade reside continuously at the division site and provide a lasting spatial reference for phragmoplast guidance. Recent studies of membrane fusion at the cell plate have revealed the contribution of functionally conserved eukaryotic proteins to distinct stages of cell plate biogenesis and emphasize the coupling of cell plate formation with phragmoplast expansion. Together with novel findings concerning preprophase band function and the setup of the division site, cytokinesis and its spatial control remain an open-ended field with outstanding and challenging questions to resolve.
This study reviews the literature related to regional entrepreneurship. It identifies the main topical perspectives, advancements and shortcomings, discusses several research gaps and proposes ways ...forward. The literature review is based on 170 peer-reviewed articles in the leading journals of entrepreneurship and regional science. The findings reveal that major debates occur within the disciplines of regional economics, sociology and economic geography, but discussions across disciplines are scant. While regional economists tend to overlook the role of contextualized agency, and thus neglect processes that may influence entrepreneurs' acting in distinctive localities, entrepreneurship scholars tend to overlook the role of the spatial and proximate contextual conditions in the entrepreneurial process. Future research should intensify its efforts on the interrelation between entrepreneurial agency and regional structuring in order to expand current understandings of which types of entrepreneurship prevail in different localities.
This article contributes to the emerging discussion on the role of context in entrepreneurship as well as the development of theorizing on rural entrepreneurship. It does so by exploring the role of ...spatial context for rural entrepreneurs. Through a case study of 28 ventures, two modes of spatializing rural entrepreneurial activities are identified in the form of resource endowments and spatial bridging. Additionally, we develop a typology of rural entrepreneurs, which captures hitherto unexplored heterogeneity within this group of entrepreneurs. Spatial context is found to be of considerable significance to the rural entrepreneurial process and hence this study contributes to a micro-level understanding of place-specific entrepreneurial practices and the non-local circulation of value that can enrich local economies.
Ovarian cancer is typically accompanied by the occurrence of malignant ascites containing large number of macrophages. It has been suggested that these tumor‐associated macrophages (TAMs) are skewed ...to alternative polarization (M2) and thereby play an essential role in therapy resistance and metastatic spread. In our study, we have investigated the nature, regulation and clinical correlations of TAM polarization in serous ovarian cancer. Macrophage polarization markers on TAMs and ascites cytokine levels were analyzed for 30 patients and associated with relapse‐free survival (RFS) in a prospective study with 20 evaluable patients. Surface expression of the M2 marker CD163 on TAMs was inversely associated with RFS (p < 0.01). However, global gene expression profiles determined for 17 of these patients revealed a mixed‐polarization phenotype unrelated to the M1/M2 classification. CD163 surface expression also correlated with the ascites levels of IL‐6 and IL‐10 (p < 0.05), both cytokines induced CD163 expression, and their ascites levels showed a clear inverse association with RFS (p < 0.01). These findings define a subgroup of patients with high CD163 expression, high IL‐6 and/or IL‐10 levels and poor clinical outcome.
What's new?
The peritoneal environment plays a critical role in the spread of ovarian cancer, ultimately becoming a malignant ascites, rich in tumor‐associated macrophages (TAMs), in advanced stages of disease. TAMs in this context have been implicated in therapy resistance and metastatic spread, though their function remains unclear. Here, TAMs from malignant ascites in patients with serous ovarian carcinoma were found to express a mixed‐polarization phenotype and highly variable levels of the surface marker CD163. Elevated CD163 was associated with early disease relapse and increased IL‐6 and IL‐10 levels. Further investigation of these changes in surface marker expression could provide insight into mechanisms of progression in ovarian cancer.
Update on plant cytokinesis: rule and divide Buschmann, Henrik; Müller, Sabine
Current opinion in plant biology,
December 2019, 2019-12-00, 20191201, Letnik:
52
Journal Article
Recenzirano
•The cortical division zone establishment is independent of a dense preprophase band.•The MAP65-hub controls phragmoplast midzone organization and phragmoplast expansion speed.•Phospholipid signaling ...instructs phragmoplast microtubule turn-over.
Many decisions made during plant development depend on the placement of the cytokinetic wall. Cytokinesis involves the biogenesis of the cell plate that progresses centrifugally and until the fusion of the cell plate with the parental cell wall. The phragmoplast facilitates the growth of the cell plate and directs it’s insertion at the cell cortex by a mechanism known as phragmoplast guidance. Communication between the phragmoplast and its destination, the cortical division zone, however, is not well understood. The preprophase band predicts the site of cell plate fusion, seemingly controlling the site of the cortical division zone establishment, but recent results suggest the role of this cytoskeletal array to be rather subtle. This is indirectly supported by certain types of phragmoplast-driven cell division in mosses and algae, which lack preprophase bands. In this review article, we summarize recent insight concerning phragmoplast expansion and guidance.
In griechischer und römischer Literatur konnte die Zuschreibung diplomatischen Ungeschicks an politische AkteurInnen Stilmittel der Negativporträtierung sein. Die Häufung der Zuschreibungen von ...undiplomatischem Benehmen an als „barbarisch“ oder „tyrannisch“ konnotierte Personen mahnt zur kritischen Skepsis. Der Topos wurde auch auf männliche und weibliche Mitglieder der argeadischen Monarchie übertragen, da diese von griechischen und römischen Autoren häufig als „barbarisch“ oder „tyrannisch“ beschrieben wurde. Im Folgenden wird dies anhand von zwei Fallbeispielen gezeigt: den diplomatischen Interaktionen von Eurydike, Gattin von Amyntas III. und Mutter Philipps II., und von Olympias, Frau Philipps II. und Mutter Alexanders III., zwei besonders prominent hervortretenden Repräsentantinnen ihrer Dynastie. Die Identifikation des Topos eines Mangels an Diplomatie als literarisches Stilmittel ermöglicht eine noch kritischere Sicht auf die literarische Porträtierung dieser beiden Agentinnen ihres Hauses. Ihre Beteiligung an diplomatischen Aufgaben wird somit der negativen Deutung entzogen, die sie oft in Antike (und Moderne) als vermeintliche „Einmischung“ oder Zeichen von „Herrschsucht“ erfuhren. Dies mag exemplarisch für die Behandlung anderer makedonischer royal women sein.
The mobilization of resources is an essential challenge for entrepreneurs. Existing research suggests that access to standard and high-quality resources is an important condition for entrepreneurial ...success, yet such resources are often out of reach for entrepreneurs. In this study, we explore entrepreneurial resource mobilization in resource-constrained peripheral locations. We identify three activities together constituting an underlying logic of spatial bricolage, defined as making do with the resources at hand in the immediate spatial context. Further, we suggest that the likelihood and prevalence of this logic of action is both situational and dispositional, as individual and contextual factors combine to generate important differences in the resource mobilization activities of the entrepreneurs. Our study contributes to a contextualized understanding of entrepreneurship by showing how spatial bricolage as a distinct logic can help entrepreneurs overcome resource constraints, and how the spatial context incorporates an important dimension of what constitutes 'at hand' in entrepreneurial bricolage.
Summary
Prior studies indicate that neutrophil extracellular traps (NETs) are associated with arterial thromboembolism (ATE) and mortality. We investigated the association between NET formation ...biomarkers (citrullinated histone H3 H3Cit, cell‐free DNA cfDNA, and nucleosomes) and the risk of ATE and all‐cause mortality in patients with cancer. In this prospective cohort study, H3Cit, cfDNA and nucleosome levels were determined at study inclusion, and patients with newly diagnosed cancer or progressive disease after remission were followed for 2 years for ATE and death. Nine‐hundred and fifty‐seven patients were included. The subdistribution hazard ratios for ATE of H3Cit, cfDNA and nucleosomes were 1·0 per 100 ng/ml increase (95% confidence interval 95% CI: 0·7–1·4, P = 0·949), 1·0 per 100 ng/ml (0·9–1·2, P = 0·494) increase and 1·1 per 1‐unit increase (1·0–1·2, P = 0·233), respectively. Three‐hundred and seventy‐eight (39·5%) patients died. The hazard ratio (HR) for mortality of H3Cit and cfDNA per 100 ng/ml increase was 1·1 (1·0–1·1, P < 0·001) and 1·1 (1·0–1·1, P < 0·001), respectively. The HR for mortality of nucleosome levels per 1‐unit increase was 1·0 (1·0–1·1, P = 0·233). H3Cit, cfDNA and nucleosome levels were not associated with the risk of ATE in patients with cancer. Elevated H3Cit and cfDNA levels were associated with higher mortality in patients with cancer.
An exploration of early modern encounters between Christian Europe and the (Islamic) East from the perspective of performance studies and performativity theories, this collection focuses on the ways ...in which these cultural contacts were acted out on the real and metaphorical stages of theatre, literature, music, diplomacy and travel. The volume responds to the theatricalization of early modern politics, to contemporary anxieties about the tension between religious performance and belief, to the circulation of material objects in intercultural relations, and the eminent role of theatre and drama for the (re)imagination and negotiation of cultural difference. Contributors examine early modern encounters with and in the East using an innovative combination of literary and cultural theories. They stress the contingent nature of these contacts and demonstrate that they can be read as moments of potentiality in which the future of political and economic relations - as well as the players' cultural, religious and gender identities - are at stake.
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